Study of Microstructure and Properties of Laser Cladding Ni60-WC + TiC Composite Coating

2020 ◽  
Vol 12 (5) ◽  
pp. 659-664
Author(s):  
Bin-Feng He ◽  
Fei Ma ◽  
Da-Yan Ma ◽  
Ke-Wei Xu
Keyword(s):  
Friction Coefficient ◽  
Laser Cladding ◽  
Surface Engineering ◽  
Composite Coatings ◽  
Scanning Speed ◽  
X Ray Diffraction ◽  
Frictional Wear ◽  
Hardness Tests ◽  
Surface Strengthen ◽  
Crystal Type

As a novel surface strengthen technology laser cladding was widely used in surface engineering. In this work, Ni60 + 25%WC + 10%TiC composite coatings were fabricated on the TC4 by laser cladding technology. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and frictional wear were used in the study of coatings. The results showed that dendrites is the main crystal type in the coatings, there were some bulk type crystal generated in 400 mm/min scanning speed. XRD results showed that some of the metalloceramics phases, such as TiC, VC, WC were formed in the coatings, some of the intermetallic compounds such as AlNi3, Al0.96B0.04Ni3, NiTi and C0.12Fe1.88 also formed, which improving the hardness, and the hardness tests results showed that the hardness of the coatings increased by 300% compared to the substrate, of above 1100 HV0.3. The max friction coefficient in 600 mm/min was 0.39, because of the unmelted TiC and WC particles fallen off from coatings, so the mechanism of the coating was abrasive wear. The friction coefficient is decreased to 0.11 and 0.19 when the scanning speed is 500 mm/min and 400 mm/min, respectively.

Microstructure and Wear Properties of Laser Synthesized Composite Coatings on Ti-6Al-4V

2012 ◽  
Vol 217-219 ◽  
pp. 1354-1358
Author(s):  
Jin Nan Zhao ◽  
Jing Liang ◽  
Sui Yuan Chen ◽  
Chang Sheng Liu ◽  
Feng Hua Liu
Keyword(s):  
Weight Loss ◽  
Laser Cladding ◽  
Powder Mixture ◽  
Composite Coatings ◽  
Scanning Speed ◽  
Pulse Frequency ◽  
Wear Property ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
Metallurgical Bonding

Ti-6Al-4V, C and TiB2 powders (71.5%Ti-6Al-4V+ 26.2%TiB2+2.3%C in wt. %) were prepasted and then laser clad on Ti-6Al-4V substrates. Laser cladding was carried out with a Nd:YAG pulse laser with the parameters of defocus length 15mm, pulse frequency 15Hz, scanning speed 2-4mm/s, electric current 200-240A. Microstructure and phases were analyzed with the Optical Microscopy(OM), Scanning Electron Microscopy(SEM) and X-Ray Diffraction(XRD). Laser cladding layers with smooth surfaces, good metallurgical bonding with no cracks and pores were formed. The average thickness of the coatings is approximately 80μm. Reactions among Ti, C and TiB2 in the laser molten pool cause in-situ synthesis of TiB, TiB2 and TiC reinforcements. The average microhardness is 836HV, which is more than twice that of the Ti-6Al-4V substrate (320HV). Friction coefficients of the cladding coatings fluctuate between 0.26-0.3. Laser cladding specimen with powder mixture of 71.5%Ti-6Al-4V+ 26.2%TiB2+2.3%C (weight loss 0.0007g after sliding 245m) possesses better wear property than that of the specimen with powder mixture of 90%Ti-6Al-4V+ 10%B4C (weight loss 0.0068g).

MICROSTRUCTURE AND WEAR PROPERTIES OF COMPOSITE COATINGS PRODUCED BY LASER CLADDING OF Ti-6Al-4V WITH GRAPHITE AND SILICON MIXED POWDERS

2005 ◽  
Vol 12 (02) ◽  
pp. 161-165 ◽  
Author(s):  
Y. S. TIAN ◽  
C. Z. CHEN ◽  
D. Y. WANG ◽  
Q. H. HUO ◽  
T. Q. LEI
Keyword(s):  
Titanium Alloy ◽  
Friction Coefficient ◽  
Laser Cladding ◽  
Energy Dispersive Spectroscopy ◽  
Composite Coatings ◽  
Transitional Zone ◽  
Test Results ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
X Ray

Composite coatings are fabricated by laser cladding of titanium alloy Ti-6Al-4V with graphite and silicon mixed powders. X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS) indicate that the coatings mainly consist of pre-eutectic TiC and eutectic Ti 5 Si 3 compounds. Test results show that the coatings exhibit a higher microhardness and a lower friction coefficient compared with the as-received sample. EPMA micrographs show that the compounds' morphology in the top zone of the coatings is different from that in the transitional zone.

MICROSTRUCTURE AND WEAR RESISTANCE OF IN-SITU SYNTHESIZED TiB2–TiC/Fe COMPOSITE COATING BY LASER CLADDING

2020 ◽  
pp. 2050046
Author(s):  
TIANWEI YANG ◽  
ZHAOHUI WANG ◽  
SHIHAI TAN ◽  
FU GUO
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Composite Coatings ◽  
X Ray Diffraction ◽  
Mixed Powder ◽  
X Ray ◽  
Material Surfaces ◽  
Metallurgical Bonding ◽  
Steel Surfaces

To increase the strength and wear resistance of material surfaces, various combinations of B4C and 80TiFe powder were mixed into a Fe60 self-fluxing alloy powder; the composite coatings reinforced by TiB2–TiC were successfully prepared on Q235 steel surfaces by laser cladding. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) were used to study the microstructure and chemical and phase composition. Microhardness and wear testers were used to investigate the mechanical properties. The results show that the interfaces of composite coatings and substrate materials are excellent for metallurgical bonding. The block-like TiB2 particles and flower-like TiC particles are uniformly distributed in the cladding coating. When the mass fraction of the mixed powder is 30%, the average microhardness of the coating is approximately 1100 HV[Formula: see text], which is 50% higher than that without the mixed powder, and demonstrates the best wear with a performance twice as better as that of the substrate.

Technology and Antimicrobial Properties of Cu/TiB2 Composite Coating on 304 Steel Surface Prepared by Laser Cladding

2019 ◽  
Vol 944 ◽  
pp. 473-479 ◽  
Author(s):  
Yu Sun ◽  
Vannghia Tran ◽  
Dao Zhang ◽  
Wen Bin Wang ◽  
Sen Yang
Keyword(s):  
Composite Coating ◽  
Laser Cladding ◽  
Abrasion Resistance ◽  
Composite Coatings ◽  
Pure Copper ◽  
Antimicrobial Properties ◽  
Scanning Speed ◽  
Atomic Ratio ◽  
Ti Powder

In this study, Cu/TiB2composite coating was in-situ prepared on 304 steel by laser cladding. This coating applies to hospitals, schools and some public places where cross infections happen more easily because of its good antimicrobial properties and abrasion resistance. Before laser cladding, pre-blend of Cu powder, Ti powder and B powder were undertaken by ball-milling in two different proportions (10% wt (Ti+B) and 20% wt (Ti+B)). And the atomic ratio of Ti and B was 1:2. After a series of experiments, the best parameters were achieved. They were laser power (950W), scanning speed (14mm/s) and spot diameter (3.8mm). Samples after laser cladding were characterized using optical microscopy, scanning electron microscopy and X-ray diffraction. The results showed that TiB2was fabricated in-situ. The dispersion degree of Cu was higher in the coating of 20% wt (Ti+B). The hardness of the 10% wt (Ti+B) coating was HRC57±4. With the increase of percentage of wt (Ti+B), the hardness of 20% wt (Ti+B) coating was HRC74±5. Both of them performed better than pure copper. Relative to pure copper, the abrasion resistance of Cu/TiB2composite coatings was more excellent. The results of antimicrobial experiments showed that, with the increase of percentage of wt (Ti+B), the antimicrobial properties were decreasing. But they still could to be considered favorable.

Laser Cladding of Zr55Al10Ni5Cu30/SiC Amorphous Composite Coatings on AZ91D Magnesium Alloy for Improvement of Corrosion Resistance

2011 ◽  
Vol 179-180 ◽  
pp. 757-761 ◽  
Author(s):  
Kai Jin Huang ◽  
Hou Guang Liu ◽  
Chang Rong Zhou
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Corrosion Property ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Good Corrosion Resistance ◽  
Az91d Magnesium Alloy

To improve the corrosion property of magnesium alloys, Zr-based amorphous composite coatings have been fabricated on AZ91D magnesium alloy by laser cladding using mixed powders Zr55Al10Ni5Cu30/SiC. The microstructure of the coating was characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The corrosion resistance of the coatings was tested in 3.5wt.% NaCl solution. The results show that the coatings mainly consist of amorphous and different crystalline phases. The coatings compared with AZ91D magnesium alloy exhibit good corrosion resistance because of the presence of the amorphous phase in the coatings.

Study on Microstructure of Laser In Situ Formation of TiBX and TiC Titanium Composite Coatings

2011 ◽  
Vol 686 ◽  
pp. 646-653 ◽  
Author(s):  
Jing Liang ◽  
Sui Yuan Chen ◽  
Chang Sheng Liu ◽  
Feng Hua Liu
Keyword(s):  
Laser Cladding ◽  
Composite Coatings ◽  
Scanning Speed ◽  
Processing Parameters ◽  
Pulse Frequency ◽  
Hexagonal Prism ◽  
Disperse Particles ◽  
The Matrix ◽  
Cladding Layers

Two kinds of mixed powders:Ti-6Al-4V/B/C and Ti-6Al-4V/B4C which are pre-pasted or synchronized fed on Ti-6Al-4V substrates separately were scanned by a 500W pulsed YAG laser to induce in situ formation of titanium composite coatings contained TiBxand TiC ceramic reinforced phases. The influences of laser processing parameters including Pulse Frequency (PF), Pulse Width (PW), Laser Power (P) and Scanning Speed (V) together with the powder proportions on the microstructure and properties of the coatings were investigated. Microstructures, phase components of the coating were analyzed by OM, SEM, TEM and XRD respectively. Experimental results show that two and more kinds of ceramic reinforcements were in situ formatted in the matrix of Ti-6Al-4V. TiB and TiC ceramics were formed evenly with the morphology of needle, tiny dendrites and disperse particles in the prepasted single path specimens. For the powder feed laser cladding layers, the ceramic reinforcements were TiB (needlelike), TiB2(hexagonal prism or rodlike), a small amount of TiC (disperse particles) and non fully reacted B4C. The microhardness increased with the increase of the amount of B4C and B+C additions. When the added B and C contents are the same, the microhardness of the coating with B4C addition is higher than that of the coating with B+C addition. The average micro-hardness of a powder prepasted (with 20 wt.% B4C addition) multi-path laser cladding layer formed under the optimized processing parameters is up to 800HV, which is more than 2 times of that of the substrate (340Hv), and the wear weight loss of the layer decreased nearly 3 times that of the substrate.

Research on the Fabrication of Bioceramic Composite Coatings Fabricated by Nd-YAG Laser Cladding

2015 ◽  
Vol 723 ◽  
pp. 852-855
Author(s):  
Ying Chun Wang ◽  
Xiang Fei Lv ◽  
Deng Jie Zhu ◽  
Shao Min Qu
Keyword(s):  
Composite Coating ◽  
Laser Cladding ◽  
Composite Coatings ◽  
New Technology ◽  
Scanning Speed ◽  
Processing Technique ◽  
Yag Laser ◽  
Cladding Layer ◽  
Ti6al4v Substrate ◽  
Average Grain Size

Laser surface cladding is a material processing technique to overlay the precursor material with the substrate to form a sound chemical and metallurgical bonding. Recently, laser cladding technique has been introduced in the bioceramic coating field. This paper presents a new technology to obtain bioceramic composite coating on Ti6Al4V substrate by Nd-YAG laser cladding. The microstructures of the mixed powders and cladding layer were investigated by scanning electron microscopy, and the compositions were analyzed by electron diffraction spectroscopy. The phases of the mixed powders and cladding layer were clarified by X-ray diffraction technology. Composite coating including HAP,Ca2P2O7,Ca3(PO4)2 and calcium titanates was successfully obtained by Nd-YAG laser cladding with pre-depositing mixed powders of CaHPO4·2H2O and CaCO3 directly on Ti6Al4V substrate. The average grain size of the mixed powders is 3μm from the image analyse software. The most important parameter that affected the completion of laser cladding was the scanning speed.

Microstructure and wear resistance of composite coating by laser cladding Ni60A/B4C pre-placed powders on Ti-6Al-4V substrate

2017 ◽  
Vol 24 (4) ◽  
pp. 541-546 ◽  
Author(s):  
Hongxia Zhang ◽  
Huijun Yu ◽  
Chuanzhong Chen
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Wear Test ◽  
Test Machine ◽  
X Ray Diffraction ◽  
Hardness Tester ◽  
The Matrix ◽  
Metallurgical Bond

AbstractThe composite coatings were fabricated by laser cladding Ni60A/B4C pre-placed powders on the surface of Ti-6Al-4V alloy for improving wear resistance and hardness of the substrate. In this research, the composite coatings were studied by means of X-ray diffraction, scanning electron microscope and energy dispersive spectrometer. The sliding wear tests were performed using MM200 wear test machine. The hardness of the coatings was tested by HV-1000 hardness tester. After laser cladding, it was found that there was a good metallurgical bond between the laser cladding coating and Ti-6Al-4V substrate. The composite coatings were mainly composed of the matrix of γ-Ni and a little Ni3Ti and the reinforcements of TiB2, TiC and CrB. The hardness of the sample of Ni60A-5B4C was approximately 2.5–3.5 times that of the Ti-6Al-4V substrate. The hardness of the sample of Ni60A-10B4C was 30% higher than that of sample 1. The wear resistance of samples 1 and 2 were 11 times and 10 times that of the substrate, respectively.

MICROSTRUCTURE AND WEAR RESISTANCE OF COMPOSITE COATING BY LASER CLADDING Al/TiN ON THE Ti–6Al–4V SUBSTRATE

2015 ◽  
Vol 22 (03) ◽  
pp. 1550044 ◽  
Author(s):  
H. X. ZHANG ◽  
H. J. YU ◽  
C. Z. CHEN
Keyword(s):  
Wear Resistance ◽  
Laser Cladding ◽  
Composite Coatings ◽  
Energy Dispersive Spectrometer ◽  
Wear Test ◽  
Test Machine ◽  
X Ray Diffraction ◽  
Hardness Tester ◽  
The Matrix ◽  
Metallurgical Bond

The composite coatings were fabricated by laser cladding Al / TiN pre-placed powders on Ti –6 Al –4 V substrate for enhancing wear resistance and hardness of the substrate. The composite coatings were analyzed by means of X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS). The sliding wear tests were performed by MM200 wear test machine. The hardness of the coatings was tested by HV-1000 hardness tester. After laser cladding, it was found that there was a good metallurgical bond between the coating and the substrate. The composite coatings were mainly composed of the matrix of β- Ti  ( Al ) and the reinforcements of titanium nitride ( TiN ), Ti 3 Al , TiAl and Al 3 Ti . The hardness and wear resistance of the coatings on four samples were greatly improved, among which sample 4 exhibited the highest hardness and best wear resistance. The hardness of the coating on sample 4 was approximately 2.5 times of the Ti –6 Al –4 V substrate. And the wear resistance of sample 4 was four times of the substrate.

scholarly journals Microstructures and Wear Resistance of FeCoCrNi-Mo High Entropy Alloy/Diamond Composite Coatings by High Speed Laser Cladding

Coatings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 300 ◽  
Author(s):  
Haijiang Wang ◽  
Wei Zhang ◽  
Yingbo Peng ◽  
Mingyang Zhang ◽  
Shuyu Liu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Composite Coating ◽  
Laser Cladding ◽  
High Speed ◽  
Composite Coatings ◽  
Scanning Speed ◽  
High Entropy Alloy ◽  
Dilution Ratio ◽  
High Entropy ◽  
High Scanning Speed

FeCoCrNi-Mo high entropy alloy/diamond composite coatings were successfully prepared by high speed laser cladding. A high scanning speed was adopted (>30 mm/s), and the effects of laser power, scanning speed, and diamond content on the microstructure and wear resistance of the composite coating were studied. The processing parameters of laser cladding had significant influence on the dilution ratio, graphitization of diamond, and wear resistance of the composite coatings. When the laser cladding parameters were 3000 W of laser power and the high scanning speed of 50 mm/s, the composite coating exhibited a uniform microstructure, the lowest dilution ratio, and the best wear resistance. The wear resistance of the composite coating was enhanced with the addition of diamond, but microcracks also increased. When the amount of diamond was 15 wt.%, the best combination of microstructures and wear resistance was obtained.

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